The present invention relates to a backup system, file server and backup method for backing up a virtual file system configured by integrating shared file systems provided by a plurality of file servers.
A file sharing server providing a shared file system for a plurality of clients to share files via a network is known. Also known is a system referred to as a Global Name Space for configuring a single virtual file system by integrating shared file systems provided by a plurality of file sharing servers, whereby the client accesses files through this virtual file system. A Global Name Space provides an environment as though the client is accessing a single file system regardless of which file sharing server among the plurality of file sharing servers configuring the virtual file system the client is connected to.
As a protocol used for backing up data stored in the shared file system provided by the file sharing server to a tape device, a protocol referred to as NDMP (Network Data Management Protocol) is known. In a backup process using NDMP, a backup server managing the backup designates a specific file sharing server to perform such backup. The file sharing server that was designated to perform the backup connects to a media server managing the tape device, and sends backup data to the media server. The media server that received the backup data writes such backup data in the tape device.
Incidentally, U.S. Pat. No. 6,026,414 refers to a file backup method of a distributed file system.